Heated nebulizer adapter for respiratory therapy

ABSTRACT

Systems, methods, and devices are described for heating nebulizer adapters. In certain embodiments, a nebulizer adapter includes a cup having an interior wall defining a gas mixing chamber, an exterior wall, and a fluid cavity disposed between the interior wall and the exterior wall. The nebulizer adapter also includes an inlet port having a fluid lumen in fluid communication with the fluid cavity and a breathing gas inlet lumen in fluid communication with the mixing chamber. The nebulizer adapter further includes an outlet having a breathing gas outlet lumen, and a drain port in fluid communication with the mixing chamber and having a drain lumen that passes from the interior wall to the exterior wall of the cup.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/008,880, filed on Jun. 6, 2014, which is hereby incorporated hereinby reference in its entirety.

BACKGROUND

Patients with respiratory ailments may be treated with respiratoryassist devices, for example devices that deliver supplemental breathinggas to a patient. Such devices include devices that deliver gas to apatient using high flow therapy (HFT). HFT devices deliver a high flowrate of breathing gas to a patient via a nasal cannula to increase apatient's fraction of inspired oxygen (FiO2) while decreasing apatient's work of breathing. Some HFT devices heat and humidify thedelivered breathing gas to reduce patient discomfort.

Patients receiving respiratory therapy may also benefit fromadministration of nebulized medications. Nebulizers allow aerosolizedrespiratory medications, such as bronchodilators (e.g., Albuterol(Ventolin), Salbutamol (Proventil), Levosalbutamol/Levalbuterol(Xopenex)) for treating asthma or Chronic Obstructive Pulmonary Disease(COPD) to be administered through inhalation directly to a patient'slungs. Nebulizers may be connected to respiratory assist devices tosupply nebulized medication together with supplemental breathing gas.Such systems can allow a patient to receive the medication withoutstopping use of a respiratory assist device.

A combination of nebulized medication and HFT can be used to assistpatients experiencing respiratory distress and provide a comfortable andeffective management of cardiopulmonary conditions. A challengeassociated with delivering nebulized medication via a high-flow systemis condensation of moisture from the mixture of heated and humidifiedbreathing gas and nebulized medication. Condensation in a ventilationcircuit presents both clinical and mechanical challenges, as thecondensate can build up to limit flow through the system and alsocollect and stagnate which presents a biologic hazard to the patient.

SUMMARY

Disclosed herein are systems, devices, and methods for heating nebulizeradapters used in respiratory therapy. In certain implementations, thesystems, devices, and methods include a nebulizer adapter with a gasmixing chamber surrounded by a fluid cavity. Nebulized medication ismixed with heated and humidified breathing gas in the gas mixingchamber. Heating fluid is passed into the fluid cavity to heat the gasmixing chamber, thereby reducing condensation of moisture from theheated and humidified breathing gas. Condensate that does collect in thegas mixing chamber is drained through a drain port. The drain port maypass the condensate into an evaporative dispersal system, a condensatetrap, an absorbent pad, or any other suitable moisture removing device.These systems devices and methods provide an effective method forreducing unwanted condensation in the ventilation circuit and formanaging condensation that does occur, thereby enabling continuous orsemi-continuous operation of high flow therapy (HFT) with nebulizedmedication. Furthermore, by locating the fluid cavity in the nebulizeradapter rather than in the nebulizer itself, a simpler nebulizer may beused which may facilitate the use of single-dose nebulizers.

The nebulizer adapter disclosed herein can be used with a wide range ofnebulizers, including vibrating mesh nebulizers (e.g., the AERONEB®nebulizer), ultrasonic nebulizers (e.g., nebulizers with a vibratingpiezocrystal), nebulizers using compressed gases, jet nebulizers,single-dose nebulizers, or reusable nebulizers. In a preferredembodiment, the nebulizer adapter is used with HFT, but the nebulizeradapter may also be used with other types of respiratory therapy andrespiratory therapy devices, including low flow oxygen therapy,continuous positive airway pressure therapy (CPAP), mechanicalventilation, oxygen masks, Venturi masks, and tracheotomy masks.

In one aspect, a nebulizer adapter includes a cup having an interiorwall defining a gas mixing chamber, an exterior wall, and a fluid cavitydisposed between the interior wall and the exterior wall. The nebulizeradapter also includes an inlet port having a fluid lumen in fluidcommunication with the fluid cavity and a breathing gas inlet lumen influid communication with the mixing chamber, an outlet having abreathing gas outlet lumen, and a drain port in fluid communication withthe mixing chamber and having a drain lumen that passes from theinterior wall to the exterior wall of the cup. In certainimplementations, the fluid lumen is concentric with the breathing gasinlet lumen.

In certain implementations, the drain port is in fluid communicationwith an evaporative dispersal system. The evaporative dispersal systemmay include a frame, a wicking layer covering the frame, and asemipermeable bacteriostatic layer covering the wicking material. Incertain implementations, a delivery tube is connected to the inlet portand the evaporative dispersal system is supported on an outer surface ofthe delivery tube along a length of the delivery tube configured to wickcondensate from a first region proximal to the drain port towards asecond region distal to the drain port. The wicking layer may be awater-insoluble biocompatible material. In certain implementations thewicking layer is a hydrocarbon.

In certain implementations, the drain port is in fluid communicationwith a condensation trap. The drain port may be connected to a glassfilter having an average pore diameter less than 0.5 microns and theglass filter is connected to an absorbent pad.

In certain implementations, the nebulizer adapter includes a plugconfigured to substantially occlude the mixing chamber when thenebulizer is not attached to the cup. Alternatively, the nebulizeradapter may include an inflatable balloon configured to substantiallyocclude the mixing chamber when the nebulizer is not attached to thecup.

In certain implementations, the fluid lumen of the inlet port comprisesa divider for separating an inflow passage for carrying fluid to the cupand an outflow passage for carrying fluid away from the cup. The outletport may be configured to connect to a nasal cannula. In certainimplementations, the outflow port includes an outflow fluid lumen influid communication with the fluid cavity and an outflow breathing gaslumen in fluid communication with the mixing chamber. The outflow fluidlumen may be concentric with the outflow breathing gas lumen.

In another aspect, a method for delivering aerosolized medicationcombined with heated and humidified breathing gas includes coupling anebulizer containing a medication to a nebulizer adapter having a mixingchamber and a fluid cavity surrounding the mixing chamber, passing aheated fluid through the fluid cavity of the nebulizer adapter to heatthe mixing chamber, nebulizing the medication and transmitting thenebulized medication into the mixing chamber, passing a heated andhumidified breathing gas through the mixing chamber and out an outletport, and passing a condensate from the mixing chamber through a drainport. In certain implementations, the method of further includes passingthe condensate into an evaporative dispersal system. In certainimplementations, the method further comprises passing the condensateinto a condensate trap. In certain implementations, the method furtherincludes passing the condensate through a glass filter into an absorbentpad.

In certain implementations, the method further includes removing thenebulizer from the nebulizer adapter, and inserting a plug into thenebulizer adapter to fill most of the mixing chamber. In certainimplementations, the method further includes removing the nebulizer fromthe nebulizer adapter, and inflating a balloon to fill most of themixing chamber. In certain implementations, the method further includescirculating the fluid in the fluid cavity. The method may furtherinclude connecting the outlet port to a nasal cannula.

In another aspect, a nebulizer adapter includes means for releasablyreceiving a nebulizer and having mixing means for mixing a heated andhumidified breathing gas with a nebulized medication and heating meansfor heating the mixing means using a fluid, means for delivering a fluidto the heating means, means for delivering heated and humidifiedbreathing gas to the mixing means, means for passing a mixed gas out ofthe mixing means, and means for draining condensate from the mixingmeans. In certain implementations, the means for fluidly connecting thefluid to the heating means is concentric with the means for deliveringheated and humidified breathing gas to the mixing means.

In certain implementations, the nebulizer adapter further includes meansfor passing the condensate into an evaporative dispersal system. Thenebulizer adapter may further include means for passing the condensateinto a condensate trap. The nebulizer adapter may further include meansfor passing the condensate through a glass filter into an absorbent pad.The nebulizer adapter may further include means for plugging thenebulizer adapter to fill most of the mixing chamber.

In certain implementations, the nebulizer adapter further includes meansfor inflating a balloon to fill most of the mixing chamber. In certainimplementations, the nebulizer adapter further includes means forcirculating the fluid in the fluid cavity. In certain implementations,the nebulizer adapter further includes means for connecting a nasalcannula to the means for passing a mixed gas out of the mixing means.

Variations and modifications will occur to those of skill in the artafter reviewing this disclosure. The disclosed features may beimplemented, in any combination and subcombination (including multipledependent combinations and subcombinations), with one or more otherfeatures described herein. The various features described or illustratedabove, including any components thereof, may be combined or integratedin other systems. Moreover, certain features may be omitted or notimplemented.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects and advantages will be apparent uponconsideration of the following detailed description, taken inconjunction with the accompanying drawings, in which like referencecharacters refer to like parts throughout, and in which:

FIG. 1 shows an illustrative nebulizer adapter;

FIG. 2 shows the nebulizer adapter of FIG. 1 coupled to a nebulizer;

FIG. 3 shows the nebulizer adapter of FIG. 1 with heating fluidcirculating in the adapter;

FIG. 4 shows a top view of the nebulizer adapter of FIG. 1 with heatingfluid circulating in the adapter;

FIG. 5 shows a cross section taken along section line A-A of thenebulizer adapter in FIG. 5;

FIG. 6 shows a top view of an illustrative nebulizer adapter withheating fluid circulating in the adapter;

FIG. 7 shows the illustrative nebulizer adapter of FIG. 1 coupled to avolume filling plug;

FIG. 8 shows the nebulizer adapter of FIG. 1 with an evaporativedispersal system;

FIG. 9 shows a cross section of the evaporative dispersal system of FIG.8;

FIG. 10 shows the nebulizer adapter of FIG. 1 and an absorbent pad;

FIG. 11 shows the nebulizer adapter of FIG. 1 coupled with a condensatetrap;

FIG. 12 shows an illustrative process for delivering aerosolizedmedication combined with heated and humidified breathing gas; and

FIG. 13 shows the nebulizer adapter of FIG. 1 in line with a high flowtherapy system.

DETAILED DESCRIPTION

To provide an overall understanding of the systems, devices, and methodsdescribed herein, certain illustrative embodiments will be described.Although the embodiments and features described herein are specificallydescribed for use in connection with a high flow therapy system, it willbe understood that all the components and other features outlined belowmay be combined with one another in any suitable manner and may beadapted and applied to other types of respiratory therapy andrespiratory therapy devices, including low flow oxygen therapy,continuous positive airway pressure therapy (CPAP), mechanicalventilation, oxygen masks, Venturi masks, and tracheotomy masks.

The systems, devices and methods described herein provide a nebulizeradapter that allows simultaneous administration of nebulized drugs andrespiratory therapy. The nebulizer adapter addresses potentialcomplications caused by condensation in the ventilation circuit byreducing risk of condensation and providing devices that removecondensate that does collect during therapy. The nebulizer adapterreduces the rate of condensation by reducing cooling due to heat loss tothe ambient environment and by reducing cooling due to gas expansionwhen breathing gas enters a mixing chamber of the adapter in whichheated and humidified breathing gas is mixed with nebulized medication.In particular, the nebulizer adapter reduces heat loss from the mixingchamber by circulating a heating fluid through a fluid cavitysurrounding the mixing chamber. To reduce cooling due to gas expansionwhen a nebulizer is not coupled to the nebulizer adapter, the nebulizeradapter is configured to receive a plug that reduces the availablevolume of the mixing chamber. In addition to reducing the rate ofcondensation, the nebulizer adapter also manages condensate that doescollect through use of one or more moisture removal systems includingevaporative dispersal systems, absorbent pads, or condensate traps.

The design of the nebulizer adapter also facilitates the use ofsingle-dose nebulizers. Single-dose nebulizers reduce the risk ofcontaminating the ventilation circuit compared to reusable nebulizers.Because the mixing chamber is heated by a fluid cavity in the nebulizeradapter instead of in the nebulizer itself, modifications to thenebulizer are not required for use with the present system. This reducesthe number of parts needed to incorporate the nebulizer, and when thenebulizer is removed and replaced, a heating fluid connection does nothave to be disconnected from the nebulizer. Instead, the heating fluidremains continuously connected to the nebulizer adapter. This designallows heating fluid to be continuously circulated and reduces the riskof spilling or contaminating heating fluid in the circuit.

The design of the nebulizer adapter also provides connection to amulti-lumen ventilation circuit. For instance, if the ventilationcircuit carries both breathing gas and heating fluid in a singledelivery tube with multiple lumens, that delivery tube may be connectedto the nebulizer adapter at a single point. This single connection pointreduces the bulk of the connection between the adapter and theventilation circuit by reducing the number of connections and tubingadapters needed compared to an adapter or nebulizer having separateports for breathing gas and heating connections.

FIG. 1 shows a nebulizer adapter for use in a respiratory therapycircuit. The nebulizer adapter 100 includes a cup 102 configured toreceive a nebulizer through an opening 101 of the adapter. The cup 102has an interior wall 104 that defines a gas mixing chamber 106 and anexterior wall 108. A fluid cavity 110 is disposed between the interiorwall 104 and the exterior wall 108. A heating fluid is delivered to andcirculated in the fluid cavity 110 to heat the gas mixing chamber 106.

The nebulizer adapter 100 also includes an inlet port 112 connected tothe cup 102. The inlet port 112 has a fluid lumen 114 and a breathinggas lumen 116. The fluid lumen 114 is in fluid communication with thefluid cavity 110 and enables a heating fluid to be delivered to thefluid cavity 110. The breathing gas lumen 116 is in fluid communicationwith the mixing chamber 106 and allows breathing gas to be delivered tothe gas mixing chamber 106. The breathing gas may be a heated andhumidified gas and have high oxygen content. In certain embodiments,breathing gas is passed into the breathing gas lumen at a rate ofbetween eight and forty liters per minute, though any suitable flow ratemay be used for a particular therapy or application. The breathing gaslumen 116 is concentric with the fluid lumen 114, and thus both heatingfluid and breathing gas can be delivered to the nebulizer adapter from adelivery tube at a single connection point. Having a single point ofconnection to a single delivery tube allows for simpler and more compactattachment (e.g., fewer tubes and connectors) compared to systems withseparate delivery tubes for breathing gas and heating fluid.

The nebulizer adapter 100 also includes an outlet 118 and a drain port119, both of which are in fluid communication with the gas mixingchamber 106. The outlet 118 passes breathing gas that has been mixedwith nebulized medication from the mixing chamber 106. The nebulizeradapter 100 may be located proximate to the patient, in which case theoutlet port 118 may be connected to a nasal cannula, or the nebulizeradapter may be located proximate to the source of heated and humidifiedbreathing gas. In such a configuration, the gas exiting the gas mixingchamber 106 through outlet 118 may be connected to a delivery tubecarrying a heated fluid to reduce condensation as discussed below inrelation to FIG. 8.

The drain port 119 on nebulizer adapter 100 removes condensate from themixing chamber 106. Condensate can form in the mixing chamber 106 due tocooling of the heated and humidified breathing gas. Condensation is aparticular concern for HFT because HFT devices supply breathing gas witha high relative humidity and a high temperature. If condensate is notmanaged, it can flood a patient's nasal passages or collect and stagnatein the ventilation circuit which presents a biologic hazard to thepatient. The collection of condensation can prevent continuous use oftherapy, because therapy may be interrupted periodically for removal ofcondensate. To address these challenges, the nebulizer adapter 100continuously eliminates condensate through the drain port 119. The drainport 119 is located at the bottom of the cup 102 such that gravity drawsthe condensate to the drain port 119. Pressure in the gas mixing chamber106 also forces the condensate through drain port 119. Drain port 119may pass condensate to an evaporative dispersal system, an absorbentpad, a condensate trap or another suitable device to remove moisture.The drain port 119 may be a small aperture to reduce the risk ofsubstantial loss of breathing gas flow. A small aperture also reducesthe risk of introduction of outside contaminants through the drain port119 into the mixing chamber 106.

While FIG. 1 shows the nebulizer adapter without a nebulizer, in use anebulizer is inserted into cup 102 as shown in FIG. 2. FIG. 2 shows thenebulizer adapter 100 of FIG. 1 coupled to a nebulizer 120. Thenebulizer 120 slides through opening 101 into the gas mixing chamber 106defined by interior wall 104. The outer wall of nebulizer 120 engages inan interference fit with interior wall 104. The nebulizer 120 may be avibrating mesh nebulizer, an ultrasonic nebulizer (e.g., a nebulizerwith a vibrating piezocrystal), a jet nebulizer, or any other suitabletype of nebulizer. Also, the nebulizer 120 may be a single-dosenebulizer or a reusable nebulizer. The nebulizer 120 dispenses nebulizedmedication into mixing chamber 106 through one or more openings onbottom face 122 of the nebulizer 120. As used herein, the term nebulizedis understood to also include aerosolized or atomized medication.Nebulized medications may include a respiratory medication, such as abronchodilator.

The nebulized medication mixes with heated and humidified breathing gasthat is passed into the mixing chamber through a nozzle 117, and thebreathing gas mixed with nebulized medication is then passed out ofoutlet 118. When the heated and humidified gas is introduced into mixingchamber 106, condensation may occur due to cooling. The condensation isundesirable because condensate could limit the gas flow through thesystem, present a biologic hazard to the patient, or could potentiallyflow into a nasal cannula and enter a patient's nasal passage.Condensation is a particular concern for HFT because HFT devices supplybreathing gas at a high flow rate. When the breathing gas is pre-heatedand humidified for patient comfort, HFT provides a high flow of gas witha high relative humidity and a high temperature. The heating andhumidifying of the breathing gas used in HFT is beneficial because highflow rates of dry breathing gas leads to patient discomfort (e.g., dueto drying of nasal passages). When heated and humidified gas cools, someof the moisture carried in the breathing gas cannot remain soluble andcondenses. With the high flow rate of HFT, there is a substantial amountof moisture in the breathing circuit that could potentially becomecondensate if the gas cools. Cooling of the heated and humidified gascan occur due to expansion of the gas as it exits nozzle 117 and entersthe gas mixing chamber 106. Cooling can also occur due to heat loss tothe ambient environment (e.g., radiative cooling at the plastic walls ofthe adapter).

The circulation of heated fluid in fluid cavity 110 reduces the coolingrelative to an uninsulated nebulizer adapter. In certain embodiments,the heating fluid entering the fluid cavity has a temperature of about43 degrees Celsius and the breathing gas entering the mixing chamber mayhave a temperature of about 35 to 43 degrees. In such embodiments, thebreathing gas is insulated and heated by the heating fluid to counteractcooling due to gas expansion. The circulation of the heating fluidincreases the convective heat transfer rate between the gas mixingchamber 106 and the fluid in the fluid cavity 110 relative to stillwater. Circulation of the heating fluid also allows the fluid tocontinuously deliver heat to the gas in the mixing chamber 106 whilebeing continuously reheated at a heating unit (not shown) elsewhere inthe circuit. The decreased cooling of the breathing gas due to theheating fluid reduces the rate of condensation in mixing chamber 106.

A perspective view of the nebulizer adapter 100 of FIG. 1 with arrows206 showing the path of the circulating heating fluid is shown in FIG.3. FIG. 4 shows a corresponding top view with the nebulizer 120 removedto show another view of the path of fluid flow through the fluid cavity110. The direction of circulation of heating fluid in both figures isindicated by arrows 206, and the direction of the flow of breathing gasis shown by arrows 202 and 204.

Referring to FIG. 4, the inlet port 112 has three passages for fluid andgas: a fluid inflow passage 114 a, a fluid outflow passage 114 b, and abreathing gas lumen 116. The use of two fluid passages allows heatingfluid to pass into and out of the fluid cavity 110, while the additionalgas lumen allows for separate transport of heated and humidifiedbreathing gas. Heating fluid enters fluid inflow passage 114 a andprovides thermal insulation within 110 before returning through fluidoutflow passage 114 b. Internal walls of the fluid cavity 110 direct theheated fluid from fluid inflow passage 114 a, around the periphery ofthe fluid cavity 110, before exiting through the fluid outflow passage114 b. Thus, the circulation of the heating fluid allows heat to becontinuously supplied to fluid cavity 110. In certain embodiments,heated fluid flows in a closed circuit so that the heating fluid iscontinuously recycled and reheated as necessary by a high flow therapyunit (not shown). The fluid circulating within fluid cavity 110, inturn, insulates the breathing gas and nebulized medication in the gasmixing chamber. After mixing, the breathing gas mixed with nebulizedmedication exits outlet 118.

FIG. 5 shows a cross section taken along section line A-A of thenebulizer adapter of FIG. 4. The cross-section shows that the breathinggas lumen 116 is concentric with a fluid lumen defined by the fluidinflow passage 114 a and the fluid outflow passage 114 b, which areseparated by divider 210. By surrounding the breathing gas lumen 116with the heated fluid, the breathing gas is insulated from ambient airand maintained at a temperature above the ambient temperature, thusreducing condensation. As discussed above, the concentric fluid lumenand breathing gas lumen may simplify connection to delivery tubing byminimizing the number of separate attachment points.

While the nebulizer adapter in FIG. 4. shows a single lumen outlet 118,the adapter outlet may have two or more output lumens to pass bothbreathing gas and heating fluid downstream in the ventilation circuit.FIG. 6 shows a top view of a nebulizer adapter 700 with the nebulizerremoved to show the path of fluid flow through the fluid cavity 710. Theoutlet 718 of the nebulizer adapter 700 has two lumens, an outflow fluidlumen 732 and an outflow gas lumen 730. The outflow fluid lumen 732 isin fluid communication with fluid cavity 710, and the outflow gas lumen730 is in fluid communication with the gas mixing chamber 706. Byproviding a fluid lumen 732 on the outlet, heating fluid that is passedinto fluid cavity 710 can be further passed into tubing that carries thebreathing gas mixed with nebulized medication out of the mixing chamber706. The outflow fluid lumen 732 surrounds the outflow gas lumen 730,and the heating fluid passed through the outflow fluid lumen 732insulates and warms the breathing gas exiting the mixing chamber 706.The outflow fluid lumen 732 may be divided into two passages, a firstpassage 732 a carrying heating fluid exiting fluid cavity 710 and asecond passage 732 b carrying heating fluid returning to fluid cavity710. The insulation and heat provided by the heating fluid in theoutflow fluid lumen 732 reduces condensation of moisture in thebreathing gas on its way to the patient. Such a configuration may bedesirable in instances where the nebulizer is located in a breathingcircuit and away from the patient (e.g., when the nebulizer adapter isproximate to the source of the heated and humidified breathing gas).

While heating the mixing chamber as discussed above reduces cooling ofthe breathing gas due to heat loss to the ambient environment, coolingdue to gas expansion can also be reduced by reducing the availablevolume of mixing chamber 106 when a nebulizer is not being used. FIG. 7shows the nebulizer adapter of FIG. 1 with a volume filling plug 300aligned to be inserted into mixing chamber 106 in place of a nebulizer.The volume-filling plug 300 has a cylindrical body 304 that mates withinterior wall 104. The cylindrical body 304 may form an interference fitwith interior wall 104 that serves to hold the volume-filling plugfirmly in position, while also sealing the mixing chamber 106 to preventthe escape of breathing gas. Insertion of the plug 300 into the mixingchamber 106 is limited by a flange 302 which makes contact with theupper surface 107 of the cup 102. The flange 302 may also form a sealwith the upper surface 107 of the cup 102 to reduce the risk of gasleaking out of the mixing chamber 106. Alternatively, the volume-fillingplug 300 may be inserted into the mixing chamber 106 until the bottomsurface of plug 306 engages the bottom surface 109 of interior wall 104.The volume-filling plug 300 has a protrusion 306 which mates with nozzle117 so that when the volume-filling plug 300 is fully inserted into themixing chamber 106, the protrusion 306 extends over both sides of nozzle117. The mating fit thus reduces the expansion of the breathing gas thatpasses through the adapter, while not blocking the flow of thatbreathing gas. In certain embodiments, a balloon is used in place of thevolume-filling plug. For example, a balloon may be built into the cup102 and inflated with saline or air when the nebulizer 120 is notinserted. Such a balloon may subsequently be deflated before reinsertionof the nebulizer 120.

Reducing cooling due to gas expansion as described above reduces therate of condensation of moisture from the breathing gas, but somecondensation may still occur in mixing chamber 106 during use. It isdesirable to remove condensate that collects in cup 102 for patientsafety. One possible means for removal of that condensate is evaporativedispersal. FIG. 8 shows the nebulizer adapter 100 of FIG. 1 coupled withan evaporative dispersal system according to certain embodiments.Although the evaporative dispersal system 400 is shown on a nebulizeradapter that has an outflow fluid lumen at its outlet, it may also bepreferable to use the evaporative dispersal system 400 in embodiments inwhich the nebulizer adapter is proximal to the patient. The evaporativedispersal system 400 is connected to the drain port 119 of nebulizeradapter 100. The connection to drain port 119 can be permanent and maybe held using an adhesive, ultrasonic weld, or another suitablepermanent attachment mechanism. Alternatively, the connection to drainport 119 may be temporary and may be held by a positive attachmentmechanism (e.g., a Luer lock) or an interference fit. The evaporativedispersal system 400 is mounted on delivery tubing 420 which isconnected to the inlet port 112. Condensate 121 that collects in cup 102may be forced by gas pressure in mixing chamber 106 to flow throughdrain port 119 into the evaporative dispersal system. The condensate maybe driven by capillary action from a region 400 a proximal to the drainport 119 towards a region 400 b distal to the drain port 119. As thecondensate is wicked along the length of evaporative dispersal system400, it also evaporates into ambient air.

A cross section of the evaporative dispersal system 400 is shown in FIG.9. The evaporative dispersal system is supported by the wall 402 of thedelivery tubing 420 and includes a frame 404, a wicking layer 406covering the frame 404, and a semi-permeable bacteriostatic layer 408covering the wicking material 406. The frame 404 may be fused to thedelivery tube 420 or bonded temporarily. The semi-permeablebacteriostatic layer 408 is affixed to the plastic frame 404. The gapbetween the inner surface of the semi-permeable bacteriostatic layer 408and the outer surface of the plastic frame is filled with the wickingmaterial 406. The wicking material 406 promotes the mobilization ofcondensate down the length of the evaporative device. The wickingmaterial 406 may be biocompatible and water insoluble. In certainembodiments, the wicking material is a hydrocarbon. A hydrocarbonwicking material may allow diffusion of the condensate while prohibitingsignificant microbiological contamination from reentering the closedsystem.

While an evaporative dispersal system may be used to remove condensatefrom the nebulizer adapter, an absorbent pad may also be used forremoval of condensate. FIG. 10 shows the nebulizer adapter 100 of FIG. 1placed over an absorbent pad 504. For simplicity, neither the nebulizeradapter nor the volume-filling plug is shown inserted in cup 102.Condensate 121 that collects in gas mixing chamber 106 exits mixingchamber 106 through drain port 119 and is passed through a filter 502.The filter allows the condensate 121 to seep through and pass into theabsorbent pad 504. In certain embodiments, the filter 502 is a glassfilter with an average pore diameter pore of less than 0.5 μm. The glassfilter allows smooth dispersal of the condensate while also keepingoutside contaminants from entering the ventilation circuit through thedrain port. Pressure inside the mixing chamber 106 can cause condensateexiting the chamber to spray, often with a whistling sound, out of thechamber. The glass filter provides for quiet dispersal of the condensatein a liquid state to be soaked up by the absorbent pad 504. The filteralso serves as a contamination shield, reducing the risk of bacteriaentering the mixing chamber 106. The absorbent pad 504 may be placed ona patient's chest such that the bottom surface 508 rests on thepatient's chest, while the upper surface 506 is exposed so thatcondensate 121 exiting filter 502 may be absorbed.

In certain applications, condensate can also be removed using acondensate trap. FIG. 11 shows the nebulizer adapter of FIG. 1 coupledwith a condensate trap 610. Condensate trap 610 is connected to thedrain port 119 on cup 102 via tubing 612. Flow of the condensate 121into the tubing 612 may be facilitated by the positive pressure insidemixing chamber 106 relative to the pressure inside the condensate trap610. A pressure differential between the mixing chamber 106 and theinside of the condensate trap 610 may be achieved due to a vented filter618 on the condensate trap 610 which allows the pressure in the interior622 of condensate trap 610 to be closer to atmosphere pressure. Thefilter material for the vented filter 618 may be hydrophobic to preventthe rapid outflow of trapped condensate 616 from the condensate trap610.

The tubing 612 is connected to the condensate trap via connector 614,which may provide a permanent attachment or a reversible positivelocking mechanism (e.g., Luer lock). A reversible positive lockingmechanism may facilitate replacement of the condensate trap. Inembodiments where a reversible positive locking mechanism is not used,the lid of the condensate trap 610 may be removable for emptying thecondensate trap 610. Although the condensate trap 610 is depicted asabout the same size as cup 102, in certain embodiments, condensate trap610 has a capacity of 1 liter or more. In such embodiments, thecondensate trap may be located on a stand included with the unit thatsupplies the heated and humidified breathing gas.

The nebulizer adapter described above, or other adapters forincorporating nebulizers and heating fluid into a breathing circuit, maybe used according to the process described in FIG. 12. FIG. 12 shows amethod 150 for delivering aerosolized medication combined with heatedand humidified breathing gas. The method outlined in flowchart 150 maybe practiced using the nebulizer adapter 100 of FIGS. 1 and 2. It willbe understood by one of ordinary skill in the art that, prior to thesteps shown in FIG. 12, a heated and humidified breathing gas may begenerated for delivery to a patient by any suitable means.

In step 152, a nebulizer containing a medication is coupled to anebulizer adapter having a mixing chamber and a fluid cavity surroundingthe mixing chamber. In step 154, a heating fluid is passed through thefluid cavity of the nebulizer adapter to heat the mixing chamber.Heating the mixing chamber can reduce cooling of the breathing gas inthe mixing chamber that can lead to condensation of moisture from thebreathing gas. In certain embodiments, the heating fluid entering thefluid cavity has a temperature of about 43 degrees Celsius which is ator above the temperature of the breathing gas in the mixing chamber tofacilitate heating of the breathing gas.

In step 156, the medication is nebulized and transmitted into the mixingchamber 106. In step 158, a heated and humidified breathing gas ispassed through the mixing chamber to entrain the nebulized medication inthe flow of breathing gas. The breathing gas mixed with nebulizedmedication is passed out of an outlet port after mixing. In someembodiments, the breathing gas has a temperature of about 35 to 43degrees upon exiting the mixing chamber. Moisture from the heated andhumidified breathing gas may condense in step 158 due to cooling effectssuch as expansive cooling and heat loss to the ambient environment.These cooling effects are mitigated by the heat and insulation providedby the heating fluid in the fluid cavity. If condensate forms despitethe heating, the condensate is passed from the mixing chamber through adrain port in step 160. In certain embodiments, the condensate is passedthrough the drain port to an evaporative dispersal system, a condensatetrap, an absorbent pad, or any other suitable moisture removing device.When the nebulizer is no longer needed or after the single-dose of asingle-dose nebulizer has been delivered, the nebulizer may be removedand a volume filling plug inserted. The volume filing plug reduces theexpansion of the breathing gas as it passes through the mixing chamberand thus may reduce cooling associated with gas expansion. The reductionin cooling can lead to a reduction in condensation.

The procedure and nebulizer adapters described above may be implementedwith the high flow therapy (HFT) system shown in FIG. 13. FIG. 13 showsthe nebulizer adapter of FIG. 1 in line with an HFT system according tocertain embodiments. The nebulizer adapter 100 is connected to deliverytubing 420, water trap 610, nasal cannula 600, and nebulizer 120. Thedelivery tubing 420 connects to the inlet port 112 of the nebulizeradaptor 100. The other end of delivery tubing 420 is connected to asource of high flow heated and humidified breathing gas (not shown). Thedelivery tubing 420 delivers both heating fluid and heated andhumidified breathing gas through at least two separate lumens. Theheating fluid delivered by delivery tubing 420 enters the fluid cavityin nebulizer adapter 100, while the heated and humidified breathing gasenters the gas mixing chamber.

The nasal cannula 600 is connected to the outlet 118 of the nebulizeradapter 100 via connector 602 so that the interior of tubing 603 is influid communication with the gas mixing chamber inside nebulizer adapter100. Heated and humidified gas mixed with nebulized medication exitsoutlet 118, travels through tubing 603, and exits out of opening 604 inthe nasal cannula 600. The cannula 600 is sized for use with infants,but any other suitable nasal cannula may be used. When the nasal cannula600 is worn by a patient, openings 604 may be inserted into thepatient's nostrils so that the heated and humidified breathing gas mixedwith nebulized medication may be injected into a patient's nasalpassages.

The foregoing is merely illustrative of the principles of thedisclosure, and the systems, devices, and methods can be practiced byother than the described embodiments, which are presented for purposesof illustration and not of limitation. It is to be understood that thesystems, devices, and methods disclosed herein, while shown for use inhigh flow therapy systems, may be applied to systems, devices, andmethods to be used in other ventilation circuits.

Variations and modifications will occur to those of skill in the artafter reviewing this disclosure. The disclosed features may beimplemented, in any combination and subcombination (including multipledependent combinations and subcombinations), with one or more otherfeatures described herein. The various features described or illustratedabove, including any components thereof, may be combined or integratedin other systems. Moreover, certain features may be omitted or notimplemented.

Examples of changes, substitutions, and alterations are ascertainable byone skilled in the art and could be made without departing from thescope of the information disclosed herein. All references cited hereinare incorporated by reference in their entirety and made part of thisapplication.

We claim:
 1. A nebulizer adapter comprising: a cup having an interiorwall defining a gas mixing chamber, an exterior wall, and a fluid cavitydisposed between the interior wall and the exterior wall, the cupconfigured to releasably receive a nebulizer; an inlet port having afluid lumen in fluid communication with the fluid cavity and a breathinggas inlet lumen in fluid communication with the mixing chamber; anoutlet having a breathing gas outlet lumen; and a drain port in fluidcommunication with the mixing chamber and having a drain lumen thatpasses from the interior wall to the exterior wall of the cup.
 2. Thenebulizer adapter of claim 1, wherein the fluid lumen is concentric withthe breathing gas inlet lumen.
 3. The nebulizer adapter of claim 1,wherein the drain port is in fluid communication with an evaporativedispersal system.
 4. The nebulizer adapter of claim 3, wherein theevaporative dispersal system comprises a frame, a wicking layer coveringthe frame, and a semipermeable bacteriostatic layer covering the wickinglayer.
 5. The nebulizer adapter of claim 4, wherein the wicking layer isa water-insoluble biocompatible material.
 6. The nebulizer adapter ofclaim 4, wherein the wicking layer is a hydrocarbon.
 7. The nebulizeradapter of claim 3, wherein a delivery tube is connected to the inletport and the evaporative dispersal system is supported on an outersurface of the delivery tube along a length of the delivery tubeconfigured to wick condensate from a first region proximal to the drainport towards a second region distal to the drain port.
 8. The nebulizeradapter of claim 1, wherein the drain port is in fluid communicationwith a condensation trap.
 9. The nebulizer adapter of claim 1, whereinthe drain port is connected to a glass filter having an average porediameter less than 0.5 microns and the glass filter is connected to anabsorbent pad.
 10. The nebulizer adapter of claim 1, further comprisinga plug configured to substantially occlude the gas mixing chamber whenthe nebulizer is not received in the cup.
 11. The nebulizer adapter ofclaim 1, further comprising an inflatable balloon configured tosubstantially occlude the mixing chamber when the nebulizer is notreceived in the cup.
 12. The nebulizer adapter of claim 1, wherein thefluid lumen of the inlet port comprises a divider for separating aninflow passage for carrying fluid to the cup and an outflow passage forcarrying fluid away from the cup.
 13. The nebulizer adapter of claim 1,wherein the outlet port is configured to connect to a nasal cannula. 14.The nebulizer adapter of claim 1, wherein the outflow includes anoutflow fluid lumen in fluid communication with the fluid cavity and anoutflow breathing gas lumen in fluid communication with the mixingchamber.
 15. The nebulizer adapter of claim 14, wherein the outflowfluid lumen is concentric with the outflow breathing gas lumen.
 16. Amethod for delivering aerosolized medication combined with heated andhumidified breathing gas, the method comprising: coupling a nebulizercontaining a medication to a nebulizer adapter having a mixing chamberand a fluid cavity surrounding the mixing chamber; passing a heatedfluid through the fluid cavity of the nebulizer adapter to heat themixing chamber; nebulizing the medication and transmitting the nebulizedmedication into the mixing chamber; passing a heated and humidifiedbreathing gas through the mixing chamber and out an outlet port; andpassing a condensate from the mixing chamber through a drain port. 17.The method of claim 16, further comprising passing the condensate intoan evaporative dispersal system.
 18. The method of claim 16, furthercomprising passing the condensate into a condensate trap.
 19. The methodof claim 16, further comprising passing the condensate through a glassfilter into an absorbent pad.
 20. The method of claim 16, furthercomprising: removing the nebulizer from the nebulizer adapter; andinserting a plug into the nebulizer adapter to fill most of the mixingchamber.
 21. The method of claim 16, further comprising: removing thenebulizer from the nebulizer adapter; and inflating a balloon to fillmost of the mixing chamber.
 22. The method of claim 16, furthercomprising circulating the fluid in the fluid cavity.
 23. The method ofclaim 16, further comprising connecting the outlet port to a nasalcannula.
 24. A nebulizer adapter comprising: means for releasablyreceiving a nebulizer and having mixing means for mixing a heated andhumidified breathing gas with a nebulized medication and heating meansfor heating the mixing means using a fluid; means for delivering a fluidto the heating means; means for delivering heated and humidifiedbreathing gas to the mixing means; means for passing a mixed gas out ofthe mixing means; and means for draining condensate from the mixingmeans.
 25. The nebulizer adapter of claim 24, wherein the means fordelivering the fluid to the heating means is concentric with the meansfor delivering heated and humidified breathing gas to the mixing means.26. The nebulizer adapter of claim 24, wherein the means for drainingcondensate is fluidly connected to an evaporative dispersal system. 27.The nebulizer adapter of claim 24, wherein the means for drainingcondensate is fluidly connected to a condensate trap.
 28. The nebulizeradapter of claim 24, wherein the means for draining condensate isfluidly connected to a glass filter configured to pass condensate intoan absorbent pad.
 29. The nebulizer adapter of claim 24, furthercomprising means for plugging the nebulizer adapter to fill most of themixing means.
 30. The nebulizer adapter of claim 24, further comprisingan inflatable means configured to fill most of the mixing means.
 31. Thenebulizer adapter of claim 24, wherein the heating means comprises aheating fluid configured to circulate around the mixing means.
 32. Thenebulizer adapter of claim 24, further comprising means for connecting anasal cannula to the means for passing a mixed gas out of the mixingmeans.